Alkylaryl and alkylmethyl organosiloxanes and methods for their preparation have been disclosed in the art. For example, Ryan in U.S. Pat. No. 3,088,964 discloses an organodisiloxane having the formula (CH.sub.3 CH(C.sub.6 H.sub.5)CH.sub.2 (R).sub.2 Si).sub.2 O wherein each R is a monovalent hydrocarbon radical free of aliphatic unsaturation, there being no more than one CH.sub.3 CH(C.sub.6 H.sub.5)CH.sub.2 -- radical per Si atom, and R is preferably methyl. Ryan also discloses a process for the production of aralkyl substituted organosilicon compounds in improved yields which comprises reacting (1) alpha-methylstyrene with (2) an organosilicon compound of the formula R.sub.x HSiCl.sub.3-x where R represents a monovalent hydrocarbon radical free of aliphatic unsaturation and x is an integer of from 1 to 2 inclusive, by contacting (1) and (2) in the liquid phase in the presence of a catalytic quantity of chloroplatinic acid, where R is preferably methyl. Ryan further discloses that the resulting addition product can be hydrolyzed with water.
Kookootsedes et al. in U.S. Pat. No. 3,186,964 disclose a composition of matter consisting essentially of a toluene soluble copolymer of (1) from 10 to 90 mole percent polymeric units of the formula (C.sub.6 H.sub.5 R--)(CH.sub.3)SiO, wherein R is an alkylene radical of from 2 to 3 inclusive carbon atoms such as ethylene or propylene, and (2) from 10 to 90 mole percent polymeric units of the formula (CH.sub.3)(R')SiO wherein R' is an alkyl radical of from 2 to 3 inclusive carbon atoms, where R' is preferably ethyl. Kookootsedes et al. further discloses several methods of preparing these siloxane copolymers, the preferred method being to first effect a reaction between alpha-methylstyrene and some of the silicon-bonded hydrogen atoms in a methylhydrogensiloxane, from 0.1 to 0.9 mole percent of alpha-methylstyrene per mole of methylhydrogensiloxane is used in the presence of chloroplatinic acid as the catalyst, the addition reaction resulting in the attachment of 2-phenylpropyl groups to some of the silicon atoms having hydrogen attached thereto, the reaction being carried out at temperatures of from 70 to 175.degree. C. After the first reaction is completed, a reaction is then effected between either ethylene and/or propylene and the remaining silicon-bonded hydrogen atoms in the copolymer, preferably an excess of ethylene and/or propylene is used so that the SiH content of the copolymer is reduced to a very small value. It is further disclosed that this reaction is also best carried out in the presence of chloroplatinic acid at temperatures of from 75 to 200.degree. C.
Pater in U.S. Pat. No. 3,221,040 discloses a copolymeric organosiloxane oil of the formula R.sub.3 SiO((CH.sub.3).sub.2 SiO).sub.x (CH.sub.3 (C.sub.2 H.sub.5)SiO).sub.w (C.sub.6 H.sub.4 (R.sup.1)-C.sub.2 H.sub.4 (CH.sub.3)SiO).sub.y SiR.sub.3 wherein R is a hydrocarbyl group, preferably methyl, R.sup.1 is selected from the class consisting of a hydrogen atom and a methyl radical, x is a number, w is a number, the sum of x and w is at least 1, y is a number of at least one, the ratio of x+w to y is from 1:1 to 3:1, and the viscosity of the copolymeric organosiloxane oil at 25.degree. C. is from 25 centistokes to 10,000 centistokes.
Legrow et al. in U.S. Pat. No. 5,384,383 disclose pristine phenylpropylalkylsiloxanes consisting of mixtures of linear and cyclic siloxanes containing the structure ##STR1##
Legrow et al. further disclose that these phenylpropylalkylsiloxanes are produced by a method comprising i) hydrolyzing a pure phenylpropylalkyldichlorosilane having a purity of greater than 99.9% and containing no detectable silicon hydride, free organics, or free inorganics and thereafter recovering the hydrolysis reaction product, and ii) equilibrating the hydrolysis reaction product with a triorganosilyl endblocker in the presence of a heterogeneous acid catalyst.
Biggs et al. in U.S. Pat. No. 5,516,870 disclose a method of making alkylmethyl cyclic siloxanes comprising (i) forming a reaction mixture containing an alpha-olefin, one or more silanol-free methylhydrogen cyclic siloxanes, and less than about 100 parts per million water, (ii) contacting the essentially anhydrous silanol-free reaction mixture with anhydrous platinum supported on carbon catalyst, (iii) agitating the mixture and catalyst to form an alkylmethyl cyclic siloxane, and (iv) continuing the reaction until the alkylmethyl cyclic siloxane is .tbd.SiH free; SiH free being the amount of hydrogen present as SiH within the detection limits of Fourier Transform Infrared Spectroscopy or less than one part per million.
Biggs et al. in U.S. Pat. No. 5,554,708 discloses a method of making linear triorganosiloxy endcapped methylhydrogen polysiloxanes comprising (i) forming a reaction mixture containing a silanol-free hexaorganodisiloxane, one or more silanol-free methylhydrogen cyclic siloxanes, and less than about 100 parts per million water, (ii) contacting the reaction mixture with anhydrous trifluoromethane sulfonic acid catalyst, and (iii) agitating the mixture and the catalyst at below 100.degree. C. to form a linear triorganosiloxy endcapped methylhydrogen polysiloxane.